From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB590C433F5 for ; Tue, 16 Nov 2021 20:25:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACD39617E4 for ; Tue, 16 Nov 2021 20:25:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230154AbhKPU2f (ORCPT ); Tue, 16 Nov 2021 15:28:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:46984 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229733AbhKPU2e (ORCPT ); Tue, 16 Nov 2021 15:28:34 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 32DD561ABD; Tue, 16 Nov 2021 20:25:36 +0000 (UTC) Date: Tue, 16 Nov 2021 15:25:34 -0500 From: Steven Rostedt To: Joe Korty Cc: Sebastian Andrzej Siewior , Thomas Gleixner , Clark Williams , Jun Miao , linux-rt-users , linux-kernel@vger.kernel.org Subject: Re: [PATCH 5.10-rt+] drm/i915/gt: transform irq_disable into local_lock. Message-ID: <20211116152534.122f8357@gandalf.local.home> In-Reply-To: <20211009164908.GA21269@zipoli.concurrent-rt.com> References: <20211007165928.GA43890@zipoli.concurrent-rt.com> <20211007171929.hegwwqelf46skjyw@linutronix.de> <20211009164908.GA21269@zipoli.concurrent-rt.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 9 Oct 2021 12:49:08 -0400 Joe Korty wrote: > On Thu, Oct 07, 2021 at 07:19:29PM +0200, Sebastian Andrzej Siewior wrote: > > On 2021-10-07 12:59:28 [-0400], Joe Korty wrote: > > > Convert IRQ blocking in intel_breadcrumbs_park() to a local lock. > > > > > > Affects 5.10-rt and all later releases, up to and including when > > > rt was merged into mainline. > > > > RT was merged into mainline? Nobody tells me anything anymore??? > > > > > This problem has been reported in two other linux-rt-users postings, > > > > > > [PREEMPT_RT] i915: fix PREEMPT_RT locking splats (Clark Williams) > > > [linux-5.12.y-rt] drm/i915/gt: Fix a lockdep warning with interrupts enabled (Jun Miao) > > > > > > Neither of these submit the obvious solution, nor, > > > AFAICT, has either yet been acted on. So I muddy the > > > waters further by submitting this, a third fix. > > > > 5.12 is longer maintained. Could you please take the latest devel tree > > for testing and participate in > > https://lore.kernel.org/all/20211005150046.1000285-1-bigeasy@linutronix.de/ > > > > If anything I would prefer those patches backported into v5.10 if it is > > affected. > > > Hi Sebastian, > Please add my 'Tested-by' to the below patch. > > [linux-5.12.y-rt] drm/i915/gt: Fix a lockdep warning with interrupts enabled (Jun Miao) > > What was tested was a backport to 5.10-rt. One reject > was encountered, trivially resolved. No other adjustments > were made. > > My regression tests of last night all passed without any > of the usual lockdep splats occuring. Prior to this, > I could be assured of a large enough flood of splats to > overwhelm the kernel log. > > My test stand is a Supermicro C7Z170-SQ. This is tthe > only system I have on which I could trigger the problem. > > I could not find this patch in the 5.12-rt or the 5.15-rt > tree, so I fetched a copy out of the linux-rt-users > archives, and backported that. > > Tested-by: Joe Korty I'm looking to see what needs to be added to 5.10-rt. Is there a particular fix in one of the 5.x-rt trees (x > 10) that I can pull from? Or is this only an issue with 5.10 and below? -- Steve